1. Field of the Invention
The present invention relates to an electronic apparatus in which the display panel having a touch panel attached to its display screen is reversible to the main body.
2. Description of the Related Art
Various types of electronic apparatuses equipped with many functions are being developed from year to year. Notebook type personal computers (hereinafter referred to as “notebook type PCs”) are a type of portable electronic apparatus. Notebook type PCs comprise a main body, keyboard on the upper surface of the main body, and display panel coupled to one side of the main body by a hinge. The display panel can rotate about the hinge between a position in which it is laid on the keyboard, and a position in which it is raised from the main body.
As other types of electronic apparatuses, there are notebook type PCs having a touch panel layered to the display screen. In these PCs, input operations can be performed using the keyboard provided on the upper surface of the main body, and input operations concerning the information displayed on the display screen can be performed by touching the touch panel with a finger or pen.
In these PCs, the hinge has a rotation axis about which the display panel is raised, and a swivel axis about which the display panel is reversed (swiveled). When an input operation is performed by using the keyboard, the display panel is raised from the main body. On the other hand, when an input operation is performed using only the touch panel, the display panel is reversed so that the rear surface of the display panel opposite to the front surface with the touch panel faces the keyboard, and is superposed upon the main body.
To keep the display panel at an arbitrary position, the hinge of the notebook type PC has a rotational resistance about each of the two axes. If a user tries to raise a display panel from the main body of a notebook type PC as indicated by arrow, the display panel may unintentionally swivel about the swivel axis as indicated by arrow while it is being rotated to the raised position.
If the display panel is rotated in a direction that differs from the direction intended by a user, the display panel may collide with, for example, a keyboard. Further, an undesirable strong force may be exerted upon a hinge, thereby damaging it. In the light of this, users must move the display panel, paying attention to the balance of the rotation and swivel operations. If the rotational resistance about the swivel axis is increased to prevent unintentional swiveling, it becomes difficult to invert the display panel.
To solve this problem, Jpn. Pat. Appln. KOKAI Publication No. 9-185430 discloses an electronic apparatus (information processing device) in which the display panel (display section) is mechanically switched between the rotation and swivel operations when the panel is reversed. This electronic apparatus employs a locking bar, which suppresses the rotation operation of the display section and enables the swivel operation only in a position in which the display section with the touch panel (resistance film screen) is perpendicular to the main body. When reversing the display section, a user raises the display section to a position perpendicular to the main body, and then operates an operation lever to move the locking bar so as to suppress the rotation operation and enable the swivel operation. After the display section is swiveled through 180°, the operation lever is again operated to move the locking bar so as to suppress the swivel operation and enable the rotation operation. Thereafter, the display section is laid upon the main body, thereby exposing the resistance film screen to the outside. In this state, a handwriting input operation is enabled.
As described above, in this electronic apparatus, while the display section is being reversed, it is necessary to operate the operation lever to switch the operation between the rotation and swivel operations. If this switching operation is performed using one hand, this hand must grip only one of the display screen and operation lever at a time, and then the other, which is very troublesome. If, conversely, the switching operation is performed using both hands, one hand needs to grip the display section and the other hand needs to grip the operation lever. This means that the electronic apparatus must be operated when it is placed on, for example, a desk.